In the semiconductor and related industries, for example, it is common to form an insulating layer of material on a silicon substrate and then form a conductive layer (generally silicon) on the insulating layer to produce what is commonly referred to as a silicon-on-insulator (SOI) substrate for use in the further growth of semiconductor devices. To achieve a desirable SOI substrate the conductive layer should be a layer of single crystal material. Further, to achieve a layer of single crystal material on the insulating layer the insulating layer generally must be a single crystal layer. In the prior art it can be seen that the formation of a single crystal insulating layer of desirable insulating material on a silicon substrate is very difficult.
In the prior art, a layer of GaN epitaxially grown on an SOI substrate has been used as a base for the further growth of semiconductor devices. Generally, the prior art deals with ways to relieve or release strain in the GaN layer to reduce stress formation and cracking in layers grown on the GaN layer. One example of the prior art is an article entitled “Improved Quality GaN by Growth on Compliant Silico-on-Insulator Substrates Using Metalorganic Chemical Vapor Deposition”, J. Cao et al., Journal of Applied Physics, Vol. 83, No. 7, (April 1998), 3829-3834. A second example is in an article entitled “Characterization of GaN layers Grown on Silicon-on-Insulator substrates”, S. Tripathy et al., Applied Surface Science, 253, (2006), 236-240. In prior art methods and devices of this type the devices are limited to materials that can be lattice matched to GaN and the materials grown on the GaN will retain all of the defects and fractures present in the layer of GaN.
In a copending U.S. patent application entitled “AlOxNy ON REO/Si”, filed 1 Nov. 2010, bearing Ser. No. 61/408,783, and incorporated herein by reference, a layer of AlOxNy, is epitaxially grown substantially crystal lattice matched to a silicon substrate. In this disclosure a layer of rare earth oxide is grown directly on a silicon substrate and one or more III-rare earth oxide layers are epitaxially grown on the rare earth oxide layer to provide a gradual crystal lattice match between the rare earth oxide and a layer of AlOxNy. The AlOxNy can then be used to grow III-N based materials for various semiconductor devices.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide new and improved materials and methods of fabricating insulative layers on semiconductor wafers.
Accordingly, it is an object of the present invention to provide new and improved strain engineered compliant substrates.
It is another object of the present invention to provide new and improved III-N layers epitaxially grown on strain engineered compliant substrates.